Internal Change Agent or Consultant?

I am doing a research paper on organizational development for an MBA class I am taking. I was wondering if anyone who has been in the organizational development field for a while could answer the following question:

Who is better able to make a lasting major organizational change for a company - an internal change agent (someone who is employed by the company) or a consultant from outside the company?

I realize it depends on many variables and depends on the situation, however, I would like to hear any thoughts you might have.

Thank you in advance for any responses!

• Internal/External Consultants by Steve Horn, 10/15/97